Marine scientists are to create 3D images of the seabed off the north of Scotland to help identify habitats that need conservation.

Waters around Noss Head near Wick and the Southern Trench, a deep channel in the Moray Firth, will be surveyed.

The Scottish government will use the images to inform marine conservation and development policies.

"Acoustic multi-beam" survey techniques will be used create the 3D images in the project, starting on Tuesday.

The Minch and the Sound of Canna, as well as Linnhe, Etive, Leven and Eil lochs will also be surveyed later in the year.

The work, which is funded by Marine Scotland, is being carried out by Scottish Natural Heritage (SNH), the British Geological Survey and the Northern Lighthouse Board as part of the Scottish marine protected area project.

Ice age gouge

The area around the Southern Trench, which is frequently visited by minke whales, features a deep and distinctive gouge in the seabed, formed during the last ice age. Relatively little is known about this area.

Scotland has responsibility for 13% of Europe's seas. They are a huge environmental, economic and recreational resourceLaura Clark, SNH project manager

A previous survey carried out off Noss Head for Scottish and Southern Energy in 2010 showed a bed of horse mussels, which SNH said could be the largest in Scottish waters. Apart from this discovery, there is scant information on marine wildlife in the area.

Laura Clark, SNH project manager for the survey, said: "We'll cover a large area during the survey which ranges from 10m to 150m deep, using the Northern Lighthouse Board vessel NLV Polestar.

"Then in September we'll carry out a detailed biological survey of areas of particular interest with scientists from Marine Scotland Science and Heriot-Watt University.

"At that stage we'll use a drop-down video camera to capture undersea footage and take grab samples from the seabed for analysis."

Ms Clark added: "Scotland has responsibility for 13% of Europe's seas. They are a huge environmental, economic and recreational resource.

"These surveys are helping us better understand the distribution and extent of the wildlife and habitats found here."

She said that would help the team advise on marine developments, and how to meet international commitments to designate marine-protected areas in Scottish waters.

The findings are expected to be published on the SNH website next spring.